Electric switch



1953 F. J. OLMER ETAL 2,849,550

ELECTRIC SWITCH Filed April 4, 195a mmvroa JACK M. CHASNOFF, JULESCHAsNoFF AND FRANCOIS J. OLMER ATTORNEY United States atent flice2,849,556 Patented Aug. 26, 1958 ELECTRIC swrrcn Francois J. Olrner,Highland Park, Ill., and Jules Chasnoff, Clayton, and Jack M. Chasnofl,Ladue, Mo.

Application April 4, 1955,.SerialNo. 576,109 9 cla ms. or. 200-33 Thisinvention relates in general to switches and, more particularly; to atime-delay switch.

It is an object of the present invention to provide a small, compact,mercury switch which will reliably and promptly effect circuit closureand cause circuit-opening after a predetermined time-interval.

It is another-object of the present invention to provide a mercuryswitch having a relatively fine, narrow and elongated capillary forconsistent yet retarded flow therethrough to effect a time delay ofdefined extent, and being so constructed asto prevent becoming boundthrough the surface tension of the mercury.

It is 'an additional objcct'of the present invention to provide amercuryswitch which is adapted for substantially instantaneous circuitclosure, which contains no moving parts, and which provides for acirculatory flow of mercury, whereby obstructionthrough air or gas locksis prevented.

It is anotherobject of the present invention to provide a mercury switchwhich is-sturdy and durable; reliable in operation; and which may beeconomically manufactured.

It is a further object of the present invention to provide a mercuryswitchfor multiple incorporation in the circuit for effecting controlfrom two locations.

These and other detailed objects are obtained by the structuresillustrated in the accompanying drawing (one sheet), in which- Figure 1is a vertical section of a mercury switch constructed in accordance withand embodying the present invention showing the switch in-circuit-opencondition.

Figure 2 is a vertical section of the switch showing same incircuiteclosed condition.

Figure 3 is a vertical section of another form of a switch constructedin accordance withand embodying the present invention.

Figure 4 is a vertical section of an; additional form of th presentinvention.

Figure 5 is a schematic diagram of a circuit incorporating switches ofthe type illustrated in Figure 4.

Referring now by reference characters to the drawing, in Figurel, Arepresents an electric switch comprising a vessel made of glass, orother nonconductive material, having a mercury charge M, and integrallycontaining a normally upper chamber 1 and lower chamber 2 which aremutually, partially offset; therebeing a common partition wall portion 3between the lower, inner section of theformer and the upper, innersection of the latter. At its-normally upper end, upper chamber 1 isprovided with a recess q. Connecting chambers 1 and 2 between theirlower ends is a fine bore, constant diameter, elongated passage orcapillary tube 4, extending along the side of the vessel and. beingupwardly curved at its lower end, as at 4', so that the mercurydischarged therefrom will be directed upwardly or laterally into thebottom of chamber 2. The lower end wall of chamber 2, as at 2',corresponds to partition wall 3, both being tapered upwardly andoutwardly at substantially the same angle to the longitudinal axis ofthe vessel, so that the lower end portions of said chambers 1, 2 are ofgeneral funnellike character, having similar volume and with the crosssections thereof increasing at the same rate, for purposes presentlyappearing. Lower chamber 2 at its upper end opens into a relativelylarge diametered return passage 5 which extends along a side wallportion of the vessel, between same and upper chamber 1, in symmetricalrelationship with capillary tube 4; being arcuated at its upper end,following the contour of the vessel wall, for opening downwardly orlaterally into the upper end of chamber 1.

Through the top, recess-containing portion of upper chamber 1 projects apair ofparal'lel contact rods or members 6, the lower ends ofwhiehterminate at a point substantially coincident with the upper end of thetapered lower end portion of said chamber 1. At their outer ends saidcontactrodso may be suitably connected to conductive leads of-a circuit(not shown). To reduce arcing, said vesselmay be evacuated or, ifdesired, may be filled with hydrogen, or other suitable gas.

In useswitch A'is mounted for operation as by a conventional togglemember- (not shown) so as to be rockable through an are of about 90*,between circuitopening and circuit-closingpositions. InFigure 1, switchA is shown in circuit-open condition, wherein the bulk of the mercurycharge M is received within lower chamher 2 and contact rods 6 are outof engagement therewith, and hence arev nonconductive.- It must be notedthat although the circuit through switch A is open, a limited quantityor residual amount of mercury remains in upper chamber 1, substantiallyfilling the tapered, lower, portion thereof, andwith its upper surfacein immediate, non-contacting adjacency to the lower ends of rods 6. Uponrocking or tilting switch A from the position shown in Figure ,1 to thatillustrated in Figure 2, the. residual mercury M in upper chamber 1 willbe brought, by gravity, into contact with rods 6, at their normallyupper ends, so that-current flow therebetween Will be reestablishedalmost instantaneously, while simultaneously mercury is being rapidlyreturned into chamber 1 through passageS to thereby cause the desiredcircuit operation, such as the. lighting of a lamp, starting ofa motor,etc. Passage 5 is of sufiicient diameter to permit free, unimpededmercury flow, without time lag, therethrough, with the result thatcontact rods 6 will be fully immersed in mercury M so that circuitclosure through switch A will be reliably. maintained.

To effect circuit opening, switelrA will be tilted or rocked restoringlyto the position shown in Figure 1. However, due to. the capillary:action involved, the circuit will not become OPQILfQIf a pre-determinedinterval after the switch hasbeen: actuated. Thus, mercury M in flowingfrom upper chamberl to lower chamber 2 must progress downwardlythroughthe narrow, elongated capillary tube 4 with such. flow,expectedly, ceasing, when the residual niercury'in upper chamber 1 andthat in the upper portion of chamber-2 will be level,- at which pointcontact rods will'becleared and hence, out of conductive relationship.Switch A is d signed so that about 45 seconds will elapse before thelevel of mercury in chamber 1 will be below contact; rods. 6 to permit apre-determined delay in operation of' the system involved, as forinstance, providing for an-area to remain in an illuminated conditionfor suflicient duration to allow an individual to move therethroughprior to light extinguishment. Thus, the residual mercury in upperchamber 1 when switch A is in opened condition Permits rapid circuitclosure, ts With switches of various types, such as mechanical, and thelike. There are myriad applications for the switch of the presentinvention, many of which are readily evident. 7

Switch A is small and most, compact, being suitably sized for home use,as in a wall switch. Heretofore, time control mercury switches of thissize have not been considered feasible for effecting the desired timelag. In the present instance the provision of the same cross section ofthe column of mercury at both ends of the capillary tube assuresuninterrupted, non-binding flow of mercury from upper chamber 1 to lowerchamber 2, since this equality of cross section prevents the surfaceension of the mercury from interfering with the continuous, smooth, andreliable flow through the relatively long capillary tube 4. It will beseen that upon rocking switch A from closed condition (Figure 2) to openposition (Figure l) a very small amount of mercury in the normally upperend of passage 5 will immediately be dropped to the lower end of chamber2 so as to establish a continuity with the mercury in the capillary tube4, and thereby, substantially, immediately forming a column of increasedcross-section so that surface tension will not interrupt the mercuryflow, as in structures heretofore utilized. Previous switches containconstricted portions or capillaries of greatly reduced length, andhence, require chambers of substantial proportions with a relativelylarge quantity of mercury to achieve a time delay. Thus, the vesselherein disclosed reveals novel structural characteristics to renderswitch A operable in its intended manner without resort to thecumbersome expedients deemed requisite prior to the present invention.It is noteworthy that switch A is so constructed as to provide for acirculatory flow of mercury, with the exception of the small amountreferred to hereinabove for prompt establishment of the circuit betweenrods 6 or for continuity with the stream through capillary 4. The novelcirculatory flow of mercury provided herein prevents the development ofany obstructing air or gas locks since the same, should switch A not beevacuated, will be moved ahead of the flowing mercury and thus directedinto open portions.

Furthermore, in the present invention, provision of a residual amount ofmercury in upper chamber 1 conduces to prompt circuit closure developingupon switch actuation, so that time delay is provided only on openingthe circuit and not in closing same. Heretofore, mercury switches havehistorically entailed time delay in both operations, as the mercury musttravel through the same constricted passage or through complicatedvalves. A time delay in circuit closure is generally undesirable andthis adverse feature is overcome by the present invention. It must alsobe noted that switch A does not incorporate any moving parts andtherefore, it is not subject to breakdown or mal-function, as is commonwith those mercury switches involving various valve members.

Referring now to Figure 3, another form of the present invention isshown, comprising a switch A having an upper chamber 1, lower chamber12, the latter being connected to the former by a relativelywide-diametered passage 5'; there being contact rods 6' extending intoupper chamber 1', all of which elements are substantially identical tothe similar elements hereinabove described in connection with switch A.Connecting the lower ends of upper chamber 1' and lower chamber 12 is anarrow, elongated capillary tube 10, the lower end of which terminatesspacedly above the bottom wall of lower chamber 12; said capillary tube10 extending along one side wall portion of the vessel. Switch A' isprovided with a mercury charge M, which is of such amount that whenswitch A is rocked into circuit-opening condition, that is, for flow ofmercury from upper chamber 1 into lower chamber 12, a quantity ofmercury will be supplied, as through gravity, from passage 5,immediately to the lower end of chamber 12, so that continuity may beestablished with the mercury flowing through capillary 10 before thesurface tension of the same shall have exceeded the pressure or thehead. It will thus be seen that in this form of the invention themercury t the usage thereof.

first flowing through capillary 10 will not form a continuous streamwith that in lower chamber 12, as is the case in connection with switchA above described. However, the space between the lower end of capillary10 and the upper surface of the mercury initially provided in the lowerend of chamber 12 is of such extent as to permit establishment of suchstream prior to the surface tension exhibiting a force greater than thepressure head causing mercury flow.

Referring to Figure 4, there is illustrated a further form of thepresent invention, which adapts the same for incorporation in a circuitfor control thereof at two locations. In this form the inventioncomprises a switch A", being a vessel having an upper chamber 11, alower chamber 22, the lower ends of which are connected by a fine borecapillary 13, and the upper ends of which are similarly connected by afine bore capillary 15, said structural features being similar to thecorresponding parts of switch A, except that the wide diametered returnpassage 5 of the latter is in this form replaced by the capillary tube15 corresponding to capillary tube 4. It will thus be seen that switch Ais completely symmetrical; there being a pair of contact rods 16 and 17projecting into chambers 1, 22, respectively. Thus, with a charge ofmercury M provided in switch A, it will be seen that in either positionone set of rods 16 or 17, as the case may be, will be in conductiverelationship, since either one chamber or the other will contain thebulk of the mercury charge. Just as in the case of switch A, residualamounts of mercury will be disposed in chamber 11 or 22 so that uponactuation of the switch immediate conductive relationship will beestablished between the theretofore disengaged contact rods. Thus,despite the fact that capillaries provide the only passages through.switch A", the substantially instantaneous closure will be effectedthrough the said residual amounts of mercury.

In Figure 5 there is schematically presented a circuit incorporating apair of switches A" which will illustrate In said figure a pair ofswitches 20, 21, respectively, are located at mutually remote points,with one of the contact rods 16 of each being mutually connected by alead 32, with the other connecting rod 16 of each switch being connectedby a conductive lead 24, 25 to a lamp 26; there being a source ofelectricity, such as a storage battery 23 provided in either lead 24 or25. One rod 17 of each switch 20, 21 is connected with the other by alead 27, while the remaining rod 17 of each switch 20, 21 is connectedby said leads 24, 25, respectively, to lamp 26. It will thus be seenthat to eifect illumination of lamp 26 the contact rods 16 or thecontact rods 17 of both switches 29, 21 must be in conductive, orcircuit-closing relationship, that is, being immersed in the mercurycharge. Iowever, if the contact rods 16 of one switch 20 or 21, as thecase may be, are in conductive relationship, while the rods 16 of theother switch are out of conductive relationship (that is, wherein thecontact rods 17 of such switch would be immersed in mercury), there willbe no electricity supplied to the lamp 26.

Thus, it will be seen that switches 20, 21 permit control of lamp 26from two remote points, so that the tilting of one switch 20 or 21 intoa position opposite to that of the other switch will cause the circuitto be opened, While if both switches are in corresponding position theswitch will be closed. Due to the residual mercury in each of thechambers the circuit will be closed promptly upon appropriate actuationof either switch, while circuit opening will be delayed for reasonshereinabove discussed, so that the desired time delay will be provided,regardless of which switch is operated.

It should be understood that changes and modifications in the formation,construction, arrangement, and combination of the several parts of theelectric switch may be made and substituted for these herein shown anddescribed without departing from the nature and principle of ourinvention.

Having thus described our invention, what we claim and desire to secureby Letters Patent is:

1. A time delay switch comprising an enclosed vessel for a charge ofconductive fluid, having first and second chambers, there being firstand second passages said passages being mutually offset in end to endrelationship, said first passage extending between the normally lowerends of said chambers, and said second passage extending between thenormally upper ends of said chambers.

2. A time delay switch as described in claim 1 wherein said chambers areoifset in end to end relationship with respect to each other, and therebeing conductive leads in at least one of said chambers.

3. A time delay switch as described in claim 1 wherein at least one ofsaid chambers is of reduced cross section at its normally lower end.

4. A time delay switch adapted for rockable movement between twoposition, said passages being mutually offset in end to end relationshipand axially parallel to each other comprising an enclosed vessel for acharge of conductive fluid having a normally upper and a normally lowerchamber, there being a relatively narrow, elongated passage connectingsaid chambers at their lower ends and a relatively wide passageconnecting said chambers at their upper ends establishing a circulatorypath for fluid flow from one chamber to the other upon rocking of saidswitch from one position to the other, the quantity of said charge ofconductive fluid being of greater volume than the volume of eitherchamber so that while one chamber is substantially full the other willcontain a residual amount of such fluid.

5. A time delay switch adapted for rockable movement between twopositions comprising an enclosed vessel for a charge of conductive fluidhaving a normally upper and a normally lower chamber, there being arelatively narrow, elongated passage connecting said chambers at theirlower ends and a relatively wide passage connecting said chambers attheir upper ends, each of said chambers having a portion of increasingcross section from the point of communication with said narrow passage.

6. A time delay switch as described in claim 5 wherein conductive leadmembers project into said upper chamber for connecting said switch in acircuit, the inner or normally lower ends of said lead membersterminating spacedly from the opening of said narrow passage and beyondthe portion of the chamber of increasing cross section.

7. A time delay switch as described in claim 5 wherein the lower end ofsaid narrow passage opens into the lower end extremity of said lowerchamber.

8. A time delay switch as described in claim 7 wherein the lower end ofsaid narrow passage terminates spacedly above the normally bottom wallof said lower chamber.

9. A time delay switch comprising an enclosed vessel for a charge ofconductive fluid having a normally upper and a normally lower chamber,there being fine first and second capillary tubes for connecting thelower and upper ends, respectively, of said chambers establishing acirculatory path for fluid flow from one chamber to the other uponrocking of said switch from one position to the other, the quantity ofsaid charge of conductive fluid being of greater volume than the volumeof either chamber so that While one chamber is substantially full theother will contain a residual amount of such fluid, and conductive leadsprovided in each chamber.

References Cited in the file of this patent UNITED STATES PATENTS UNTTEDSTATES PATENT OFFICE CETTHUTTE QT 'CQRREQ'HN Patent No 2,849,550 August26, 1958' Francois J0 Olmer et al.

It is hereby certified that error appears in the-printed specificationof the above numbered patent requiring correction and that the saidLetters Patent should read as corrected below.

Column 5 lines 20 to 22, strike out said passages being mutually offsetin end to and relationship and axially parallel to each other" andinsert the same after "fluid" and before the period in line 33, samecolumn; same column 5, line 20, for position" read M positions n Signedand sealed this 25th day of November 1958.

(SEAL) Attest:

KARL H.,. AXLINE ROBERT C. WATSON Attesting Officer Commissioner ofPatents UNITED STATES PATENT OFFICE CERTIFIQATE OF CORREUHQN Patent No,2,849,550 August 26, l958 Francois J Olmer et a1.

It is hereby certified that error appears in the-printed specificationof the above numbered patent requiring correction and that the saidLetters Patent should read as corrected below.

Column 5, lines 20 to 22 strike out said passages being mutually offsetin end to end relationship and axially parallel to each other" andinsert the same after "fluid" and before the period in line 33, samecolumn; same column 5, line 20, for "position" read positions Signed andsealed this 25th day of November 1958.

(S Attest:

KARL H VAXLINE Attesting Officer ROBERT (I. WATSON Commissioner ofPatents

